Self or soul. Used in the Quran as a general designation for the self or true self; interpreted as the spiritual reality of all living creatures. In philosophy, the specifically human nafs is often described as the potential to actualize the fullness of self-awareness, often equated with the intellect (aql). In Sufism, often described as the “lower self,” associated with physical rather than spiritual impulses, by contrast to ruh, understood as the “soul” or “higher self.” Often understood primarily in a negative sense. In the more theoretical Sufi writings, also used in the neutral, philosophical meanings.